Tag: chemistry

Questions Related to chemistry

On the basis of following features identify the correct option:
I. This metal is not obtained in free state.
II. This metal is obtained by electrolysis of their chlorides in molten state.

chemistry metals and non metals refining of metals basics of metallurgy basic metallurgical processes

  1. $Na$

  2. $Ca$

  3. both (1) and (2)

  4. neither (1) nor (2)

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Correct Option: C
Explanation:

Both Sodium and calcium are highly reactive metal oxides are not reduced by carbon and these metals are obtained in free state by electrolytic reduction of their molten chloride salts.

In electrolytic refining, which one is the anode and which is cathode?

chemistry metals and non metals refining of metals basics of metallurgy basic metallurgical processes

  1. Pure metal is the anode and impure metal is cathode

  2. Impure metal is made anode and pure metal cathode

  3. Both can be done interchangeably

  4. None of the above

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Correct Option: B
Explanation:

In electrolytic refining, impure metal is made the anode and a thin strip of pure metal is made the cathode.

Why refining of metals is required?

chemistry metals and non metals refining of metals basics of metallurgy basic metallurgical processes

  1. They are hard

  2. They are impure

  3. They are lustrous

  4. They are malleable

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Correct Option: B
Explanation:

Refining of metals is required because the metals that have been extracted by concentration of ore are still impure.

Separation of impurities from the extracted metals is known as __________.

chemistry metals and non metals refining of metals basics of metallurgy basic metallurgical processes

  1. distillation

  2. roasting

  3. calcination

  4. refining

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Correct Option: D
Explanation:

Separation of impurities from the extracted metals is known as refining of metals.

Impurities present at anode are deposited at the bottom and called as _______.

chemistry metals and non metals refining of metals basics of metallurgy basic metallurgical processes

  1. anode dust

  2. anode particulate

  3. anode mud

  4. anode impurities

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Correct Option: C
Explanation:

In the electrolytic refining the process the impure sample is used as anode and pure metal is obtained at cathode. Impurities present at anode are deposited at the bottom and called as anode mud.

Refining of aluminium is done by __________.

chemistry metals and non metals refining of metals basics of metallurgy basic metallurgical processes

  1. electrolysis

  2. distillation

  3. sedimentation

  4. oxidation

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Correct Option: A
Explanation:

Refining of aluminium is done by electrolytic method. The aluminium obtained is 99.99% pure.

Which of the following is not a method of refining?

chemistry metals and non metals refining of metals basics of metallurgy basic metallurgical processes

  1. Roasting

  2. Electrolysis

  3. Distillation

  4. Oxidation

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Correct Option: A
Explanation:

Roasting is the method of converting the ore to its oxide form . It is not a method of refining.

When stones are separated from rice, we throw away the solid component.

chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

  1. True

  2. False

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Correct Option: A
Explanation:

When stones are separated from rice, we throw away the solid component. Stones are non useful whereas rice are useful. So we through away non useful solid and then we can have rice for cooking.

During extraction of metals, electrolytic refining is used to obtain pure metals. Material which will be used as anode, for refining of silver metal by this process, is:

chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

  1. zinc

  2. impure silver

  3. pure silver

  4. iron

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Correct Option: B
Explanation:

Electrolysis is the dissolving of metal from one electrode of an electrolytic cell to another electrode in pure form. It gives the highest purity metal product. The impure silver is cast into a slab which is the anode, while pure silver sheet metal is the cathode.

Sodium is obtained by the electrolysis of:

chemistry production of metals refining of metals basics of metallurgy basic metallurgical processes

  1. an aqueous solution of sodium chloride

  2. an aqueous solution of sodium hydroxide

  3. fused sodium chloride

  4. fused sodium sulphate

Show answer
Correct Option: C
Explanation:

Sodium is obtained by the electrolysis of fused mixture of $NaCl$ and $CaCl _2$ (Down's process). Reaction can be written as:

$2NaCl \rightarrow 2Na + {Cl} _2$